/**
 * @a https://leetcode.cn/problems/que-shi-de-shu-zi-lcof/description/
 */

#include "common.h"
class Solution
{
public:
    int takeAttendance(vector<int> &records)
    {
        int left = 0, right = records.size() - 1;
        while (left < right)
        {
            int mid = left + (right - left) / 2;
            if (records[mid] == mid)
                left = mid + 1;
            else
                right = mid - 1;
        }
        return left;
    }
};

class Solution
{
public:
    int takeAttendance(vector<int> &records)
    {
        int left = 0, right = records.size() - 1;
        while (left < right)
        {
            int mid = left + (right - left) / 2;
            if(records[mid] == mid) left = mid + 1;
            else right = mid;
        }
        return right == records[right] ? right + 1 : right;
    }
};